Sperm Selection through Microvesicle-Mediated ChemotaxisInduced by Follicular Fluid and Cumulus Cells

Area of Science:

• Reproductive Biology
• Biotechnology
• Assisted Reproductive Technology

Background:

• Selecting competent sperm is vital for successful intracytoplasmic sperm injection (ICSI).
• Chemotaxis-based sperm selection offers a promising approach to identify spermatozoa with enhanced motility and fertilization potential.
• Microvesicles (MVs) derived from follicular fluid (FF) and cumulus cells (CCs) are investigated as potential chemoattractants.

Purpose of the Study:

• To evaluate sperm selection efficacy using chemotaxis induced by FF- and CC-derived MVs.
• To assess the impact of MVs on sperm parameters within a microfluidic device.
• To determine the optimal concentration of FF-MVs for sperm enrichment.

Main Methods:

• Follicular fluid (FF) and cumulus cells (CCs) were collected from women undergoing ICSI.
• Microvesicles (MVs) were isolated from FF and CCs and characterized.
• Sperm selection was performed in a microfluidic system using semen from normozoospermic men, with MVs incorporated into agar plates to create chemoattractant gradients.
• Sperm concentration, motility, progressive motility, and DNA integrity were analyzed post-selection.

Main Results:

• Isolated FF- and CC-derived MVs exhibited characteristic morphology and physicochemical properties.
• No significant differences in sperm parameters were observed with CC-derived MVs compared to the control.
• Follicular fluid-derived MVs (FF-MVs), particularly at 50 μg/mL, significantly improved sperm concentration, progressive motility, and DNA integrity compared to controls.

Conclusions:

• Follicular fluid-derived microvesicles (FF-MVs) demonstrate chemoattractant properties.
• FF-MVs can selectively enrich sperm populations with superior functional parameters.
• FF-MVs represent a novel and effective tool for enhancing sperm selection in ICSI procedures.